Landast-8影像的水体指数构建及稳定性研究

Research on the construction and stability of the water index of Landast-8 images

针对水体提取精度易受泥沙悬浮物和山体阴影影响的问题,该文以兰州市附近的黄河流域及刘家峡水库为实验区,构建了一种新的水体指数(WI2021)。选取黄河流域水体、长江流域水体、城市水体以及出海口区域的4个测试点,用Landsat-8影像数据实验。结果表明,与已有的7种水体指数相比,WI2021以平均总体精度、Kappa系数、错分和漏提误差分别为95.53%、0.9058、6.08%和5.15%,总体上较其他水体指数具有一定的优势。该文利用Landsat-8影像的6个波段,构建了一个能够稳定地提取地表水且对泥沙悬浮物和山体阴影有较好抑制作用的水体指数。

Aiming at the problem that the water extraction accuracy is easily affected by suspended sediment and mountain shadows,this paper used the Yellow River Basin and Liujiaxia Reservoir near Lanzhou City as the experimental area to construct a new water body index(WI2021).Four test points in the water body of the Yellow River Basin,the water body of the Yangtze River Basin,the urban water body and the estuary area were selected,and the Landsat-8 image data was used for the experiment.The results showed that,compared with the existing seven water body indices,the average overall accuracy,Kappa coefficient,misclassification and omission errors of WI2021 were 95.53%,0.9058,6.08%and 5.15%,respectively,which was generally better than other water body indices.The innovation of this paper was to use the 6 bands of the Landsat-8 image to construct a water index that could stably extract surface water and had a good inhibitory effect on suspended sediment and mountain shadows.